The present invention relates to a waterproof shoe with sole or mid-sole molded onto the upper.
The possibility of manufacturing a fully waterproof shoe by injection-molding the sole or mid-sole directly onto the upper (with a lining provided with a functional waterproof and breathable membrane), appropriately associated by means of stitches to an assembly insole and fitted therewith onto an upper-holding last, is already known in the shoemaking field.
With this construction, there are problems linked to the fact that the stitches for connecting together the upper and the insole perforate the functional membrane, which accordingly becomes permeable to water, compromising the characteristic of being waterproof.
In order to solve these problems, a shoe has been provided which is disclosed in EP 298360 and comprises a breathable upper internally associated with a lining having a membrane which is permeable to vapor and impermeable to water, an insole perimetrically associated with the upper and the lining, and a sole made of a material which is impermeable to water and is injection-molded under the insole and around the edge region of the upper.
The lower edge of the lining protrudes further downward than the upper, and in this region the upper is replaced by a porous connecting element (in particular by a mesh) which is sewn to the upper on one side and to the insole and lining on the other side.
In this manner, the porosity of the material of the connecting element allows the material of the sole while liquid, during the step for injection-molding, to penetrate and close all the stitch holes.
Usually, a band of polyester mesh is used for the material of the connecting element; such band is a scarcely elastic body and therefore is unable to stretch perfectly, especially in the region of the heel and toe of the shoe.
This causes difficulties in production and in particular lack of uniformity during the step of injection-molding, with consequent formation of channels and lack of waterproofing.
The shoe disclosed in U.S. Pat. No. 5,505,011 is also known.
This shoe comprises a breathable upper internally associated with a lining having a membrane which is permeable to vapor and impermeable to water, an insole which is sewn perimetrically to the lower edge of the lining and protrudes further downward than the upper, and a sole which is made of a material impermeable to water and is injection-molded below the insole and around the edge region of the upper and of the lining.
The lining and the upper are joined together in the edge regions by means of adhesive.
This shoe is difficult to manufacture because of the different elasticity of the lining and of the upper, which leads to the formation of unaesthetic creases.
Moreover, problems in terms of lack of waterproofing have been noted and are due to fact that the upper cannot be glued at the same height along the entire perimeter of the lining.
The aim of the present invention is to provide a waterproof shoe with sole or mid-sole molded onto the upper which eliminates the above mentioned drawbacks of the prior art.
Within this aim, an object is to provide a shoe which can be conveniently manufactured either with a sole which is simply waterproof or with a sole which is both waterproof and breathable.
Another object is to provide a shoe whose cost is competitive with respect to that of known shoes of the same type.
This aim and these and other objects and others which will become better apparent hereinafter are achieved by a waterproof shoe whose structure comprises:
a breathable upper, internally associated with a lining with a membrane which is permeable to vapor and impermeable to water,
an insole, peripherally associated with the upper and the lining,
a sole or mid-sole, made of a material which is impermeable to water and is directly injection-molded at least around the edge region of the assembled upper, lining and insole,
the shoe being characterized in that the lower edge of said lining protrudes further downward than said upper and in that in said region said upper is replaced by a connecting element which is joined to said upper on one side and to the insole on the other side, said connecting element comprising waterproof material compatible, in terms of adhesive bonding, with the molding material of said sole or mid-sole.